Resins from epoxidized liquid polybutadiene and neutral esters of polybasic acids



where R is selected from the group consisting "of H and 2,946,756 Patented July 26, ,1 960 United States Patent "ice and (3) to 35 percent of saidunits are selectedv from 2,946,156 the group consisting of RESINS rRoM Eroxrmznn LIQUIDPOLYBUTA- ,f

DIENE AND NEUTRAL ESTERS OF POLYBASIC 6 I 7 CH ACIDS 1 g Jar-on,- Charles E. Wheelock and John E. Wicklatz, Bartlesville, CH I I(E}l CH 0kla., assignors to Phillips Petroleum Company, a corporation of Delaware 7 g 0E1 CHi No Drawing. Filed Dec. 13,1957, Ser. o. 702,514 9 V 19 Claims. ci.260-z a d -CH --CH=CH--CH This invention relates to resins from epoxidizefl liquid at least 1 percent, preferably 10 to 80 percent, of the polybutadiene and neutral esters-of polybasic acids. In total oxygen being Present as hydroxyl oxygen, and (B) copending apphcauonfii Senal 612,890: filed 0.1 to 50 parts of a neutral ester of an acid selected from her 1956 and Sena-1 5 filed December the group consisting of ortho titanic acid, ortho boric acid, 1956, of Wheelock, epoxldized diene polymers have been sulfurgus acid and ortho silicic acid and a monohydric described. These epoxy compounds are those wherem aliphatigalcohol boiling below 0 C.

an oxygen atom bridges adjacent carbon atoms, said carbon atoms being joined by a single valence bond. It is further disclosed therein that these. polymers are useful as resins for varying uses such as laminating, casting, and coating compositions. I have now discovered another curing system for epoxidized polymers of this type. 2

The following are objects of my invention.

An object of this invention is to provide thermosetting resins. A further object of this invention is to provide an improved curing system for epoxidized liquid polybutadiene. 1

Other objects and advantages of this invention will be come apparent to one skilled in the art upon reading the accompanying disclosure. p

The present invention relates to thermosetting" resins comprising a mixture of epoxidized liquid 'polybuta'diene containing at least 1 percent, preferably 10to 80 percent, of the total oxygen as hydroxyloxygen and, based upon 100 parts of said epoxidized po1ymer,'0.1to SQpaIts' of a neutral ester of a polybasic acid. More specifically, these resins comprise a mixture of (Alepoxidize'd liquid polybutadiene characterized in that the 'original'unsatw I rated portion of the molecule is converted by theepo'xidation reaction to units of which (1) 8 to 70 percent of said units are selected from thegrou'p consisting of The liquid polymers can be prepared by any suitable amounts of mercaptan modifiers in emulsion polymerization systems to produce liquid polymers and by mass or solution polymerization using finely divided alkali metal catalysts. A particularly preferred method is the solution polymerization described in Crouch 2,631,175. The products, following epoxidation, are preferably liquids having a viscosity up to 500,000 centipoises within the temperature range 0 to 100 C.

The epoxidized polymers are blended and reacted with neutral esters in the practice of this invention. The esters which have been found highly effective for development of rigid structures include ester of ortho titanic acid [Ti(OH) boric acid [B(OH) ortho silicic acid '[Si(OH) and sulfurious acid [OS (OH) ferred esters are those of the saturated and unsaturated monohydric alcohols which are liquids having a boiling point below about 200 C. and more preferably below 150 C. Thus, esters of the aliphatic alcohols having one cohols are methanol, ethanol, l-propanol, l-propenol, 2- propanol, l-butanol, Z-butanol, 2,-methyl-1-propanol, ,l-

pentanol, '2-pentanol, 2,2-dimethyl-1--propanol,2-methyl- 3-butyne-2-ol, 2-methyl-3-butene-2-ol, 2.-methyl-1-buta'nol, l-hexanol, and allyl alcohol.

' Insome instances, the esters can be prepared directly 0 v from the acid and the alcohol. Alternatively, other H methods using, for example, salts of the acids, aliphatic fi halides, the acid chlorides, etc., can be used. For example, the neutral esters of ortho-silicic acid can be prepared from silicon tetrachloride and ethyl alcohol as indicated by the reaction SiCl +4HOC H Si(OC H +4HCl Since sulfurons acid is unstable, indirect means are employed for the production or" the corresponding esters.

. Examples of these esters include tetraethyl titanate,

and

(2) upto 82 percent of said units are selected from the group consisting of tetraisopropyl tit-anate, tetrabutyl titanate, trimethyl bo- RQ. l rate, triethyl borate, tri-n-amyl borate, dimethyl sulfite, di-

hexyl sulfite, divinyl sulfite, di-n-amyl sulfite, tetraethyl l silicate, tetra-n-propyl silicate, tert-butyl-tri-n-amyl titanand I ate, methyldiethyl borate and triallyl borate.

OR R p The amount of esters to use should besufiicient to accelerate the rate of cure or crosslinking of the polymer. Commonly from 0.1 to 50 parts by weight of ester for each 100 parts by Weight of polymer are used. However, larger amounts of ester can be utilized advantageously in some formulations. Many of the preferred esters are liquids which can be easily blended with the polymers and serve simultaneously as a thinner or solvent. However, organic solvents can be mixed with the polymer and/or the ester to give blends which may be readily brushed or O i k-R Where 1 is Selected om the roup ons st ng of a ky aryl, alkaryl, and aralkyl groups of 1 to 20 carbon atoms method for preparing these including the use of sufficient I The pre-' to six carbon atoms are preferred. Examples of these 81- sprayed. Suitable solvents include cyclohexanone, chloroform, methyl ethyl ketone, toluene, benzene, xylene, and carbon tetrachloride. Liquid monomers such as styrene which can copolymerize with the polymer can also be efiectively used as a thinner.

Pigments, dyes, fillers, catalysts, and hardeners can be blended with these compositions to achieve special etfects. Titanium dioxide can be used to formulate a white enamel. Wood flour, glass (powdered, fibrous, cloth), sand, carbon black, mica, asbestos and other resins or plastics can be blended into the mixture.

Acid or basic catalysts or hardeners can be used in conjunction with the polymer-ester mixture, but such reagents are preferably added justprior to use of the mixture. Commonly they can be used in amounts up to 10 percent by weight of the polymer in the mixture. The acid catalysts include the inorganic acids and acid anhydrides such as sulfuric acid, phosphoric acid, phosphorus pentoxide; certain salts of polyvalent metals such as the chlorides of titanium and tin. The basic catalysts include inorganic bases such as lime, lead oxide and sodium hydroxide; and amines such as ethylenediarnine.

The conditions for cure of these compositions depends upon the particular compositions. During the initial stages of cure as indicated by absence of gelation, the

conditions should prevent undue loss of the ester. Pressure can be applied, if desired, so as to permit increase in temperature without volatilization of the ester. Generally it will be preferred to maintain the temperature between 50 and 200 C., commonly between 75 and 150 C. In some cases it is convenient to maintain a rather constant temperature during the cure period. .In other cases, the temperature can be gradually increased.

Curing periods of one to 200 hours at temperatures of 50 to 100 C. can be adequate. At higher temperatures, e.g. 150 to 200 C., the curing period can be on the order of 1 to 10 hours, but longer curing periods can be used if desired.

In the following examples, the base resin was prepared as follows:

Liquid polybutadiene, prepared accordingto the methd of Crouch 2,631,175 and having a viscosity of about 1500 Saybolt Furol seconds at 100 F. and an unsaturation of 80 percent of theoretical, e.g., 0.8 double bond per C unit, Was stripped in a batch operation by flushing for 45 minutes with nitrogen at a temperature of 190 to 200 C. and at a pressure of to 20 mm. Hg absolute. This polymer was epoxidized by dissolving 432 grams of the polymer in two liters of chloroform to which was added 280 grams of a nuclear sulfonated ion exchange resin (Amberlite IR--1'20) in the acid form and 35 mls. of glacial acetic acid. The temperature was 43 C. To this drous sodium sulfate and the solvent was stripped by warming under vacuum.

The thus prepared epoxidized polymer was then analyzed for epoxy oxygen content and total oxygen content. Epoxy oxygen contentwas determined by the hydrochloric acid-dioxane method given in Organic Analysis, Mitchell et al.; volume 1, pages 135-136, Interscience Publishers, Inc., New York (1953). Total oxygen content was determined by pyrolyzing the sample in an atmosphere of nitrogen, converting the oxygen compounds formed to carbon monoxideby passage of the gases over carbon at a temperature of 1120" C., passing the gases through a liquid nitrogen trap to remove interfering substances, oxidizing the carbon monoxide to carbon dioxide by means of copper oxide kept at a temperature of 300 C., collecting the resulting carbon dioxide in a liquid nitrogen trap, and, after pumping out the residual gases by means of a vacuum pump, determining the carbon dioxide manometrically in a standard volume.

Several batches of the polymer were prepared according to the above method and blended. Analysis of this blend showed it to contain 5.4 percent by weight of oxirane oxygen, 1.9 percent by weight of hydroxyl oxygen and a total oxygen content of 9.3 percent on the same basis. Approximately 21 percent of the total oxygen was hydroxyl oxygen. The polymer contained 0.27 atom of epoxy oxygen, 0.09 hydroxyl group, and 0.05 ester group for each aliphatic double bond originally present in the liquid polybutadiene.

The following examples illustrate the curing of the oxygen containing polymer with various neutral esters. The specific amounts shown are given for the purpose of illustration but the invention should not be considered unduly limited thereby.

EXAMPLE I For each run the above epoxidized polymer was mixed with the ester and the mixtures were placed in closed containers which were placed -in an oven maintained at C. Observations were made at various intervals of time. After 168 hours the products were cooled'to room temperature and the Shore A hardness was measured. The results presented in Table I, show that the gelation time was reduced by the addition of an ester and the Shore A hardness was increased. After measuring the Shore A hardness, the products were placed in open dishes in a vacuum oven at C. for 66 hours. After removing the products from the oven and coolingto room temperature the Shore D hardness was measured. These results are recorded in thelast column of Table I and also show that the ester-epoxidized polymer mixtures cured to a greater extent, as measured by the hardness, than the polymer without ester.

Table I Parts Observations at; 100' 0. after Shore A Run No. Ester Ester/100 hardness Shore D parts after hardness polymer 25 hr. 66 hr. hr. 168 hr 1 Nona O. 0 G91... 0 35 2 Tetralsopropyl titanate. 21. 3 Gel. 4 54 3 Trl-n-amyl borate 27. 2 Gel. 10 62 4 Di-n-amyl sulfite 22. 2 Gel. 10 59 mixture there was added 266 grams of 50 percent hydro- EXAMPLE II gen peroxide over a period of 30 to 40 minutes while maintaining the temperature at 43 C. The mixture was stirred for 2.5 hours at this temperature. The ion exchange resin was removed by filtration. Then 500 milliliters of water were added, the aqueous phase was removed, and the polymeric product washed several times with dilute aqueous sodium bicarbonate and then with water. The neutral organic phase was dried over anhy- 5 6 Table II and ([312. OR Parts/100 a ts ShoreD hardness after curln polym r p at 100 (Lforg a Run 5 where R is selected from the group consisting of H and Tetra O lsopro- Ethanol 48 hr. 96 hr. 166 232 pyl tib1. hr. ;..C; .R tanate v 1 where R is selected from the group consisting of alkyl, 1. 0 0 1 4 5 aryl, alkaryl, and aralkyl groups of 1 to 20 carbon atoms g- 8 8:5; 9, a 5% and (3) 10 to 35 percent of said units are selected from 4. 1. 31 1 31 7 2o the group consisting of 5- 1. 74 1. 74 10 17 23 25 6- 2. 61 2. e1 12 2o 25 25 CH: 7- 3. 4s 3. 4s 11 20 25 25 H s. 4.35 4.35 15 25 3o 32 15 CH int-on,-

EXAMPLE III H H -CHrC-CCH2 For the formulations-shown 1n Table III below, the O CH epoxidized polymer-ester formulations were mixed with either phosphorus pentoxide or diethylenetriamine. The 20 O mixtures were heated 168 hours at 100 C. in closed conand tainers. The Shore D hardness was then measured at a room temperature. CHT OH=CH OH"' These tests when compared with the results of Table I at least 1 percent of the total oxygen being present as show that phosphorus pentoxide or diethylenetriamine 25 hydroxyl oxygen, and (B) 0.1 to parts of a neutral can increase the'rate of cure. In making this comparison ester of an acid selected from the group consisting of it should be emphasized that the Shore A scale measures ortho titanic acid, ortho boric acid, sulfurous acid, and soft gels and rubbers, and the Shore D values apply to ortho silicic acid and a monohydric aliphatic alcohol the harder plastics. boiling below 200 C.

Table III Parts er 100 a ts f 'xidi ed 1 Run a p p Z Dory-met Shore!) No. 7 hardness Ester Amount Gatalyst Amount 1.-.. Tetraisopropyl titanate-.. 21.3 Phosphorus pentoxtde- 6 52 2 Trl-n-amly borate 27.2 do 5 9 3 Tetraisopropyl tltanate..- 21.3 Diethylene trlaminm. 6 27 4.-.- Trl-n-amylborate 27.2 do -r 6 '29 Tetraethylorthosllicate... 15.6 Phosphoruspentoxida 6 6 6.... do 15.6 Diethylene trlamlne- 6 54 The products prepared according to my'irivent-ion and as shown in the examples have particular utility in the plastics and coating, arts. They provide excellent bases for the production of protective surface coatings; varnishes, enamels, and adhesives. prepared also. The resins have good heat stability, high electrical resistance, and resistance toward many common solvents, acids and alkalis.

As many possible embodiments can be made of this (1) 8 to 70 percent of said units are selected from the group consisting of and I (2) up to 82 percent of said units are selected from the group consisting of RO-CH:

RO- n p H-orn- Molded articles can be 45 2. A curable composition comprising a mixture of parts (A) epox-idized liquid polybutadiene characterized in that the original unsaturated portion of the molecule is converted by the epoxidation reaction to units of which (1) 13 to 50 percent of said units'are selected from the groupconsisting of and (2) 50 to 77 percent of said units are selected from the group consisting of RO-OH:

RO- H H-CHzand OR OR --CHI(IJHCIIHOH2 where R is selected from the group consisting of H and 0 ll --C--R1 where R is selected from the group consisting of alkyl, aryl, alkaryl, and aralkyl groups of l to 20 carbon atoms and (3) 10 to 35 percent of said units are selected from the group consisting of and at least 1 percent of the total oxygen being present as hydroxyl oxygen, and (B) 0.1 to 50 parts of a neutral ester of an acid selected from the group consisting of ortho titanic acid, ortho boric acid, sulfurous acid, and ortho silicic acid and a monohydric aliphatic alcohol boiling below 200 C.

3. The composition of claim 1 wherein ortho titanic acid.

4. The composition of claim 1 ortho boric acid.

5. The composition of claim 1 sulfurous acid.

6. The composition of claim 1 ortho silicic acid.

7. The composition of claim 1 ester is tetraisopropyl titanate.

8. The composition of claim 1 ester is tri-n-amyl borate.

9. The composition of claim 1 wherein ester is di-n-amyl sulfite.

10. The composition of claim 1 wherein ester is tetraethyl orthosilicate.

11. The composition of claim 1 containing up to 10, percent by weight of a catalyst selected from the group consisting of stannic chloride, phosphorous pentoxide, and diethylenetriamine.

said acid is wherein said acid is wherein acid is wherein acid is wherein neutral wherein said neutral said neutral said neutral 12. The method of curing epoxizied liquid polybuta- (2) up to 82 percent of said units are selected from the group consisting of RO-CH:

RO-GH CH--CHawhere R-is selected from the group consisting of H and Il --0--R where R is selected from the group consisting of alkyl, aryl, alkaryl, and aralkyl groups of 1 to 20 carbon atoms and (3) 10 to 35 percent of said units are selected from the group consisting of at least 1 percent of the total oxygen being present as hydroxyl oxygen comprising adding to parts by weight of said material 0.1 to 50 parts of a neutral ester of an acid selected from the group consisting of ortho titanic acid, ortho boric acid, sulfurous acid, and ortho silicic acid and a monohydric aliphatic alcoholic boiling below 200 C., and heating the mixture at a temperature of 50 to'200" C., said heating being sufiicient to produce a hard resin.

13. The method of claim 12 wherein said ester is tetraisopropyl titanate.

.14. The method of claim 12wherein said ester is tri-namyl borate. W

15. The method of claim 12 whereinsaid ester, is di-namyl suliite.

16. The method claim 12 wherein said ester is tetraethyl orthosilicate.

17. A curable composition comprising a mixture of 100 parts of epoxidized liquid polybutadiene containing No references cited.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,946,756 July 26 1960 Charles E. Wheelock et a1 It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters .Patent should read as corrected below.

Column 8, line 32 for "alcoholic" read alcohol line 42, after "method" insert of line 52 for "1 9 percent hydroxy" read 1.9 percent hydroxyl Signed and sealed this 4th day of April 1961,

E Q ERNEST W. SWIDER WXXXXXEX ARTHUR w. CROCKER Attesting Oflicer Acting Commissioner of Patents 

1. A CURABLE COMPOSITION COMPRISING A MIXTURE OF 100 PARTS (A) EPOXIDIZED LIQUID POLYBUTADIENE CHARACTERIZED IN THAT THE ORIGINAL UNSATURATED PORTION OF THE MOLECULE IS CONVERTED BY THE EXPOXIDATION REACTION TO UNITS OF WHICH (1) 8 TO 70 PERCENT OF SAID UNITS ARE SELECTED FROM THE GROUP CONSISTING OF 